The phrase "a serious problem since" is correct and usable in written English.
It can be used to indicate that a significant issue has been ongoing or has developed over a period of time.
Example: "The lack of funding has become a serious problem since it affects our ability to complete the project on time."
Alternatives: "a significant issue since" or "a major concern since".
That's a serious problem, since the process for making strategic decisions can shape the strategy itself.
At first glance, this is not a serious problem, since the impact on predictive accuracy should be small.
So it could be a serious problem, since nowadays high-fructose corn syrup can be found in just about everything.
The establishment of time equivalence of Permian strata between different areas has been a serious problem since the mid-19th century.
It presents a serious problem since recently clinical efficacy of the number of cancer vaccines has been demonstrated that focused a lot of public attention.
The Supreme Court decided that this unreliability is not a serious problem, since librarians can simply disable filters at the request of adult users.
The occurrence of big deformation in tunneling had become a serious problem since 1906 when an extremely big deformation was found in the Simplon Tunnel that is located between Italy and Switzerland [1, 2].
Undoubtedly, TB itself has reemerged in India as a serious problem since 1985 with the advent of HIV/AIDS [ 2].
For a methodology that is designed to pick out particular solutions, this non-uniqueness property is a serious problem, especially since there is usually no obvious way of deciding which Nash equilibrium will end up being selected.
"We know we have a serious problem, especially since poverty and illiteracy rates are still very high," explains Veronica Umaru, national coordinator for WOTCLEF.
That was an indication of a very serious problem, since the plane was assigned to an altitude of 31,000 feet and was supposed to stay there to avoid other traffic.
